Propulsion arrangement for craft which move in a fluid medium

ABSTRACT

A hull is configurated as a lifting body, for instance as an airfoil, teardrop or the like. At its leading end portion one or more undulator units are mounted, each having one or more vanes which rotate about an axis normal to the longitudinal axis of the hull. This produces an undulatory fluid stream flowing opposite the intended direction of movement and providing the desired thrust. Alternate sweeping of the undulatory fluid stream over surfaces of the hull downstream of the units causes deundulation of the stream which increases the propulsive thrust.

C United States Patent [151 3,666,2 1 2 Schmidt [451 May 30, 1972 54 PROPULSION ARRANGENIENT FQR 3,215,371 11/1965 Schmidt ..244/62 3,111,928 11/1963 Schmidt CRAFT WHICH MOVE IN A FLUID MEDIUM Primary Examiner-Trygve M. Blix 72 Inventor: Wllhelm Schmidt, Dresden, Germany [73] Assignee: Deutsche Akldemlc Der Wiesemchnflen [57] ABSTRACT Bern. krlmAdlershof' Germany A hull is configurated as a lifting body, for instance as an air- [22] Filed; M" 10, 1970 foi1, teardrop or the like. At its leading end portion one or more undulator units are mounted, each having one or more [21] Appl- No.1 39,059 vanes which rotate about an axis normal to the longitudinal axis of the M". This produces an undulatory fluid stream flowin opposite the intended direction of movement and provid- (52] U.S. Cl ..244/62 in he desired thrust Alternate sweeping of the undulamry -M39/00 fluid stream over surfaces of the hull downstream of the units [5'] Field of Search ..244/62; I 14/67 A causes deundulation of the stream which increases the propulsive thrust. [56] References Cited UNITED STATES PATENTS 9 Claims, 3 Drawing Figures 3,068,642 12/ 1962 Schmidt ..244/62 BACKGROUND OF THE INVENTION The present invention relates generally to propulsion arrangements, and more especially to propulsion arrangements for craft which move in a fluid medium.

In my prior U. S. Pat. Nos. 3,111,928 and 3,215,137] Ihave disclosed driving or propulsion arrangements of the general type here in question, for land-, water-and air-craft. The basic concept involved is to provide a hull in the region of its trailing end with a device for undulating a fluid stream which flows from the leading end towards the trailing end and which may be produced in various ways. The undulated stream is then caused to become deundulated by impinging alternately against the opposed sides of a profiled deundulator which is arranged downstream of the undulator. For more specific details, reference may be had to the above-mentioned U. S. Patents.

In these prior constructions the undulator and the deundulator are invariably arranged at the trailing end of the hull. I have now found that it is not only desirable but possible to substantially improve the efficiency of these arrangements, and in addition to impart to craft which are so constructed a greatly enhanced degree of stability and of maneuverability.

SUMMARY OF THE INVENTION It is, accordingly, an object of the invention to provide the above outlined improvements.

A more particular object is to provide a propulsion arrangement of the type under discussion which has a substantially improved degree of propulsion efficiency.

Another object is to provide such an arrangement which allows better maneuverability of a craft so provided.

Still a further object is to provide an arrangement of this type whose use substantially enhances the stability of a craft which utilizes the arrangement.

In pursuance of the above objects, and others which will become apparent hereafter, the invention resides, briefly stated, in a propulsion arrangement of the type under discussion which combines a hull configurated as a lifting body and propulsion means including drive means and undulator means. The latter is driven by the former and produces an undulatory rearwardly flowing fluid stream which is deundulated by contact with surfaces of the hull. According to the invention the undulator means is located ahead of or at the leading portion of the hull so that the latter can, as just pointed out, serve to effect deundulation of the fluid stream.

The hull is a lifting body," which is to say that it provides lift" or buoyancy in a fluid medium. It may be airfoil shaped, teardrop shaped, or it may have positive buoyancy as by being provided with gas-filled compartments or the like. In any case, the hull itself constitutes a deundulator for the fluid stream and this increases the thrust of the same. The thrust will be the larger, the more the leading end portion of the hull is conformed to the elongate shape of the vanes utilized in the undulator device.

The arrangement according to the present invention is intended for use in conjunction with the undulator/deundulator drive provided at the trailing end of the hull, as known from my aforementioned prior U. S. Patents. When used in this manner, my novel arrangement substantially improves the thrust, reduces resistance to movement, increases the stability of the hull about its longitudinal axis, and improves the maneuverability of the craft.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a diagrammatic side view of a craft provided with a propulsion arrangement according to the invention;

FIG. 2 is a top plan view of FIG. I; and

FIG. 3 is a diagrammatic perspective of another embodimerit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing firstly FIGS. 1 and 2, it will be seen that the hull 1 here is of airfoil-shaped profile. It has an unusually dimensioned cabin whose length is greater than its width, contrary to the arrangement which is customary in such craft. At the trailing end of the hull l I provide a rotary undulator unit 2 and a stationary deundulator unit 3. These are of the type discussed at length in my aforementioned prior patents and are therefore not in need of detailed explanation.

According to the invention I provide an additional undulator unit 4 at the leading end of the hull I. As FIG. 2 shows, the unit 2 comprises four vanes arranged along an axis of rotation which extends transversely to the longitudinal axis of the hull, and the unit 4 according to the present invention is similarly subdivided. Of course, fewer or more vanes could be chosen, if desired in accordance with specific requirements. Drive means 5 are provided for the vanes of unit 2, and drive means 6 for those of unit 4. In each case, a planetary-gear drive is also provided for purposes of driving, adjusting and controlling the various vanes. Such drive means and drives are not specifically shown in detail because they are known, e.g. from my aforementioned patents to which reference may be had.

The deundulator consists of two superposed vanes each of which is subdivided as in the case of the units 2 and 4. The vanes of unit 3 are adjustable with reference to one another but do not rotate. The stabilizer 7 with the elevator 8 is located above the unit 3, as far as possible outside any turbulent fluid flow. Reference numeral 9 identifies the sidewalls of the craft, and their trailing ends are configurated (see especially FIG. 2) as lateral stabilizers l0 and carry the rudders l I.

Rotation of the vanes of units 2 and 4 by their respective drives 5 and 6 causes the vanes to convert a portion of the imparted energy into thrust. The residual energy attempts to flow off rearwardly in form of wave energy, that is in form of an undulatory fluid stream. However, this stream impinges either upon the hull l or the device 3, both of which serve to deundulate the fluid stream and thus to convert the escaping energy into thrust. This substantially improves the thrust capacity of the units 2 and 4, and the suction eflect exerted by the unit 2 in addition serves to reduce the resistance offered by the hull l to forward motion, especially if the hull is relatively thick.

It has already been pointed out that the vanes of the units 2 and 4, as well as those of the unit 3, can be adjusted in their relative positions. If the vanes of the unit 2, and those of the unit 3, are adjusted to strongly positive position, that is with their trailing edge facing downwardly, then the fluid stream about the hull 1 is deflected strongly in downward direction with a concomitant strong increase in the lift.

A further increase in lift can be achieved by also and simultaneously adjusting the vanes of unit 4 in negative sense to an extent greater than that used during normal flight. The lift attainable with these measures is so substantial even for a hull having a greater depth than width, that such a hull is enabled to fly. This is analogous with the effect obtained by a jet stream deflector, but the use of the undulator units 2 and 4 affords by contrast with such a deflector a greater efficiency and a substantial reduction of the total resistance.

Furthermore, the rotating units 2 and 4 serve as stabilizers which prevent undesired tilting or rolling of the hull about its longitudinal axis. The Stabilizers 7 and 10 serve, as in conventional airplanes, for stabilizing the hull against movement about its transverse and vertical axes, respectively. The rudders 11 and 8 provide directional control and, if operated in identical sense, serve for vertical control purposes, while they serve for lateral control if operated in opposite senses.

Naturally, and as already pointed out, the invention is not limited to flying craft or to hulls having an airfoil-shaped profile. It is also applicable to hulls of airships and underwater craft which float in their respective medium and require no dynamic lift. Such hulls are usually of more or less teardropshaped configuration. This would not be entirely advantageous in conjunction with the already described configuration of the vanes of the unit 4, and it is therefore advantageous to modify the leading end of the hull in such a case (at least over the width of the unit 4) to cooperate better with the unit 4.

Such a construction is shown in FIG. 3 by way of example. The hull is here identified with reference numeral la and has teardrop-shaped lateral walls 12 which may be provided with windows 13.

The units 2 and 4 correspond to those in FIGS. 1 and 2. The deundulator unit 3a is provided for the same purpose as the unit 3; however, it is provided with elevators 8a for vertical control. Reference numeral 14 identifies supports for the unit 4, and the front portions of the supports 14 are provided with vertical rudders 15 which are turnable about respective upright axes 15a.

In this as in the preceding embodiments, the intimate connection of the propulsion arrangements with the hull results in a substantial decrease of resistance offered by the craft to movement through its respective fluid medium. Here, also, the unit 2 serves the additional purpose of producing suction on the boundary layer of fluid flowing along the hull; it prevents separation of the boundary layer in the region of the trailing end and thus permits the use of exceptionally thick, and hence shorter, hull shapes.

During movement of the craft shown in FIG. 3, the rudders II and 8a control the direction of displacement. The latter rudders serve as light rudders and transverse rudders, depending upon whether they are moved in identical or in opposite directions. This is of course already known.

However, the craft can be directionally controlled even if it floats without a forward component of movement. The vanes of units 2 and 4 rotate in clockwise direction; if they are for instance adjusted in slightly negative sense, meaning with their rear or trailing edge upwardly inclined, then they will provide forward propulsion. If, on the other hand, the hull is to be lifted or lowered, then the vanes of the units 2 and 4 must be adjusted slightly positive or strongly negative, respectively.

By adjusting the vanes of unit 4 to provide rearward propulsion, and those of unit 2 to provide forward propulsion, with adjustment of the rudders 15, 11 in identical directions, the fluid stream producted by the units 2 and 4 is deflected laterally in the same direction and its component of thrust compensated in direction lengthwise of the hull; this results in displacement of the hull in parallelism with itself to one side or the other, depending upon the adjustment of the rudders l5, 1 I.

On the other hand, if the units 2 and 4 are operated asjust described but the rudders 15 are moved in a direction opposite that of the rudders II, the hull II will rotate in place and about an upright axis. This movement, incidentally, is achievable also without using the rudders if the units 2 and 4 each have a set of vanes located at one side of the hull and a separate set located at the other side of the hull, with each set being independently controllable as to its rotation. In that case, the sets of vanes of the units 2 and 4 at one side of the hull are rotated to produce forward thrust, and the sets of vanes at the other side are rotated to produce reverse thrust, with resultant turning ofthe hull in place.

Naturally, the craft of FIG. 3 could also be utilized as a lighter-than-air flying craft. In that case, the main hull would accommodate gas-filled cells while cabins for passengers and/or holds for cargo would be provided in the sidewalls 12, with still other possibilities suggesting themselves readily to those skilled in the art.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a propulsion arrangement for craft which move in a fluid medium, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended I. In a propulsion arrangement for craft which move in a fluid medium, a combination comprising a hull configurated as a lifting body and having a leading end portion and a trailing end portion; and propulsion means for said hull, including leading undulator means arranged at said leading end portion of said hull and having a size being a fraction of the size of said hull, said hull acting as deundulator for said leading undulator means, said leading undulator means being operative for producing an undulatory propulsive fluid stream flowing in the direction towards said trailing end portion and providing propulsive thrust for said hull, with the latter acting as deundulator means for at least in part deundulating the fluid stream whereby the propulsive thrust thereof increases, trailing undulator means on said trailing end portion and operative for providing an additional undulatory propulsive fluid stream in the region of said trailing end portion, trailing deundulator means for deundulating said trailing propulsive fluid stream, and drive means for said undulator means.

2. In a propulsion arrangement as defined in claim 1, wherein said hull is of airfoil profiled configuration.

3. In a propulsion arrangement as defined in claim 1, wherein said hull is configurated as a buoyancy body.

4. In a propulsion arrangement as defined in claim I, wherein said leading undulator means comprises at least one undulator unit, and wherein said hull has surfaces located downstream of said unit and being alternately swept by said undulatory fluid stream whereby the latter is deundulated at least in part and its propulsive thrust increases.

5. In a propulsion arrangement as defined in claim 4, said hull having a longitudinal axis coincident with the intended direction of propulsion; and wherein said leading undulator unit comprises at least one vane extending and being mounted for rotation about an axis of rotation normal to said longitudinal axis.

6. In a propulsion arrangement as defined in claim 5; further comprising at least one additional vane extending in parallelism with the first-mentioned vane and mounted for rotation with the same about said axis of rotation.

7. In a propulsion arrangement as defined in claim 4; further comprising at least one additional leading undulator unit similar and adjacent to the first-mentioned leading undulator unit.

8. In a propulsion arrangement as defined in claim 1, wherein said trailing undulator means comprises at least one trailing undulator unit, and wherein each of said undulator units comprises at least two vanes respectively rotatable about axes of rotation normal to the longitudinal axis of said hull.

9. In a propulsion arrangement as defined in claim 8, wherein the relative positions of the two vanes of at least one of said units are adjustable. 

1. In a propulsion arrangement for craft which move in a fluid medium, a combination comprising a hull configurated as a lifting body and having a leading end portion and a trailing end portion; and propulsion means for said hull, including leading undulator means arranged at said leading end portion of said hull and having a size being a fraction of the size of said hull, said hull acting as deundulator for said leading undulator means, said leading undulator means being operative for producing an undulatory propulsive fluid stream flowing in the direction towards said trailing end portion and providing propulsive thrust for said hull, with the latter acting as deundulator means for at least in part deundulating the fluid stream whereby the propulsive thrust thereof increases, trailing undulator means on said trailing end portion and operative for providing an additional undulatory propulsive fluid stream in the region of said trailing end portion, trailing deundulator means for deundulating said trailing propulsive fluid stream, and drive means for said undulator means.
 2. In a propulsion arrangement as defined in claim 1, wherein said hull is of airfoil profiled configuration.
 3. In a propulsion arrangement as defined in claim 1, wherein said hull is configurated as a buoyancy body.
 4. In a propulsion arrangement as defined in claim 1, wherein said leading undulator means comprises at least one undulator unit, and wherein said hull has surfaces located downstream of said unit and being alternately Swept by said undulatory fluid stream whereby the latter is deundulated at least in part and its propulsive thrust increases.
 5. In a propulsion arrangement as defined in claim 4, said hull having a longitudinal axis coincident with the intended direction of propulsion; and wherein said leading undulator unit comprises at least one vane extending and being mounted for rotation about an axis of rotation normal to said longitudinal axis.
 6. In a propulsion arrangement as defined in claim 5; further comprising at least one additional vane extending in parallelism with the first-mentioned vane and mounted for rotation with the same about said axis of rotation.
 7. In a propulsion arrangement as defined in claim 4; further comprising at least one additional leading undulator unit similar and adjacent to the first-mentioned leading undulator unit.
 8. In a propulsion arrangement as defined in claim 1, wherein said trailing undulator means comprises at least one trailing undulator unit, and wherein each of said undulator units comprises at least two vanes respectively rotatable about axes of rotation normal to the longitudinal axis of said hull.
 9. In a propulsion arrangement as defined in claim 8, wherein the relative positions of the two vanes of at least one of said units are adjustable. 